Internal combustion engine exhaust system



1945- E. v. RIPPINGILLE 2,370,259

INTERNAL-COMBUSTION ENGINE EXHAUST SYSTEM 7 fdzaa m Filed Oct. 16, 1941 Patented Feb. 27, 1945 Edward V. Rippingille, Detroit, Mich., assignor to General Motors Corporation, Detroit, Mich., a

corporation of Delaware Application October 16, 1941, Serial No. 415,164

14 Claims.

v To silence the exhausts of internal combustion engines it has been the general practice to provide a silencer of one'kind or another to which the several cylinders of 'the engine were connested through a manifold. This practice, in the case of engines with cylinders whose exhaust periods'overlap, adversely affects the power of the engine because the pressure of and the. pulsa-' tions in the exhaust gases discharged from one cylinder interferes with the discharge of exhaust gases from the cylinder whose exhaust period its exhaust period overlaps. The elfect is, of course, especially pronounced in the cases of two-stroke cycle engines in which the combustion s'upport-.

ing air or combustible mixture is introduced into the cylinders of the engine while their exhaust are open.

'I'he undesirable condition under consideration can, of course, be obviated by providing on engines with cylinders whose exhaust periods overlap two or more separate exhaust systems but this, of course, is an expensive practice.

This invention resides in, an exhaust system forinternal combustion engines which includes -a silencer whichis so constructed and so connected to a cylinder or cylinders and another cylinder or cylinders whose exhaust period or periods the exhaust period or periods of the former overlaps or overlap that the pressure of and the pulsations in the exhaust gases discharged from the former do not interfere with the discharge of exhanst gases from the latter. Utilization of the invention, consequently, makes it possible to employ orran engine with cylinders whose exhaust periods overlap the exhaust periods of other cylinders a single exhaust system with a single silencer without any adverse effect on the power of the engine- For a better understanding of the nature and objects of the invention reference is made to the following specification and the accompanying drawing in which are described and. illustrated preferred embodiment of the invention.

the accompanying. drawing.

1 isa front elevation. of admin-151? (cite-'29) In the drawing the reference character l0 indi-' cates a two-stroke cycle internal combustion engine with four U cylinders ll disposed radially and equiangularly spaced around the crankshaft. The cylinders fire successively in the order in' which'they are arranged around the'crankshaft and the exhaust period of each cylinder overlaps that of the cylinder which fires immediately before it.

To silence the exhaust of the engine Hi there are provided two silencers l2. Each of the silencers includes a shell 13' which is roughly e'lliptical in cross section and heads I 4 which are se-" cured to and close the ends of the shell. Through the shell extend two exhaust gas tubes I5 whose ends are secured in openings in the heads. The

' axes of the tubes I5 lie in the plane of the major axis of the shell and the tubes are spacedffrom each other and symmetrically disposed with respect to the minor axis of the shell. The tubes (5 are like the center tube of the silencer shown in Figures 1, 2 and 3 of the Wilson PatentNo. 2,332,543, dated October 26,. 1943, in that each consists of a tube l6 riddled throughout itslength withrelatively large (e. g, 4") diameter circu-f lar) perforations I'I snu lytelescoped and fixed within a. tube l8 riddled throughout its length with relatively small ,('e; g., 7 diameter circular) perforations l9. The compartment defined by the shell [3, the heads l4 and the tubes [5 is subdivided lengthwise by partitions 20' which are secured to the shell and through whi'ch the tubes extend into chambers M which communicate as side branches with the tubes through the perforations I] and l8. 7

. The silencers H. are. installed on the. engine ID with one end of each of the exhaust; gas tubes l5 of one connected to the exhaust port of one. of two of the cylinders l l which fire in immediate succession and one end of each of the exhaust gas tubes l 5 of the other connected to the exhaust, port of one of the other two cylinders. To the other end of each of, the exhaust gas tubegis con,-

nejc'ted a tail pipe 22. 'Io'corn e'ctthe silencers to the engine there are provided elbowelike meme bers23 secured at one end to the cylind'ers'and. at the other toimperforate extensions 2 1 of the exhaust gas tubes. The elbow likemembers113 are gradually enlarged from the points at which they are connectedto the extensions 24 to the points at which they are connected to the cylinders, and, in. conjunction with domed members 25 which: also communicate with the cylinders when their exhaust ports are open, form expansion chambers.

in the exhaust gases.

When the engine III is operating, exhaust gases pass from the cylinders II into the expansion chambers formed by the domed members 25 and the elbow-like members 23 and thence, through the elbow-like members, the exhaust gas tubes I5 of the silencers I2 and the tail pipes 22, to the atmosphere. The chambers 2| and the openings I1 and I9 through which they communicate with the exhaust gas tubes I5, of course, constitute resonators which are preferably so tuned, as set forth in the Wilson Patent No. 2,323,955, dated July 13, 1943, that they will resonate to and thus attenuate sound waves to which the exhaust noise of the engine is attributable.

' The exhaust gases discharged from the cylinders I I which are connected to one of the silencers I2, of course, cannot interfere with the discharge of exhaust gase from the cylinders which are connected to the other of the silencers. The provision in each of the silencers of a separateexhaust gas tube for each of the cylinders to which it is connected efiectually minimizes interference by the exhaust gases discharged from one with the discharge of exhaust gases from the other of the cylinders. This because of the resistance offered by the openings I I and I9 to the transmission of the pressure of and the pulsations in the exhaust gases in one of the tubes I5 to the exhaust gases in the other, both absolutely and relatively to the resistance ofiered by the tubes and the tail pipes 22 to the transmission thereof to the atmosphere, and the dissipative action of the chambers 2|, acting in their capacity of expansion chambers, on the pressure of and pulsations The expansion chambers formed by the domed members 25 and the elbowlike members 23 further minimize interference by the exhaust gases discharged from one of the cylinders with the discharge of exhaust gases from the other of the cylinders connected to the same silencer by the dissipative action of each expansion chamber on the pressure of and pulsations in the exhaust gases which reach it from the cylinder to which it is connected or from the other of the cylinders by way of the chambers 2 I. The invention, therefore, makes it possible to silence the exhaust of an engine with a plurality of cylinders whose exhaust periods overlap with practically no interference by the exhau t gases discharged from one of the cylinders with the dis- The exhaust'periods of the oppositely disposed cylinders of the engine I0 do not overlap. From this and what has been said, it should be clear that the exhaust of the engine II) or any other engine in which the exhaust period of no cylinder is overlapped by the exhaust period of more than one other cylinder can be silenced with one exhaust system and one silencer like that here disclosed with practically no interference by the discharge of exhaust gases from any ..cylinder with the discharge of exhaust gases from any other cylinder by connecting the cylindersfin their firing order alternately to one and the other exhaust gas tube of the silencer. This would, of course, in the case of the engine I 0 mean connectingboth cylinders II of each oppositely disposed pair to one of the exhaust gas tubes of the silencer. In the case of the engine shown,

this was not done simply because of theimpracticability in the installation in which the engine was to be used of the arrangement of exhaust piping which would have been required.

Cal

It will, I think, be obvious from what has been said that the exhausts of engines in which the exhaust period of a cylinder. is overlapped by the exhaust periods of more than one other cylinder may be silenced with one exhaust system and one silencer with practically no interference by the discharge of exhaust gases from any cylinder with the discharge of exhaust gases from any other cylinder with one exhaust system and one silencer like that herein disclosed but with exhaust gas tubes equal in number to the cylinders by whose exhaust periods the exhaust period of another cylinder is overlapped. It should also, I think, be clear from what has been said that the invention is applicable to the intake as well as the exhaust systemsofinternal combustion engines.

I claim:

1. In a two stroke cycle internal combustion engine with four cylinders which are disposed radially and spaced equiangularly around the crankshaft and fire successively in the order in which they are arranged around the crankshaft with the exhaust period of each cylinder overlapping the exahust period of the cylinder which fires immediately before it, a silencer which includes two ducts of which one is connected to the exhaust port of a cylinder and the other to the exhaust port of the cylinder which fires immediately after it, a shell which encircles the ducts and with them defines a compartment, partitions which subdivide the compartment lengthwise into a plurality of chambers of which each communicates with the ducts as a side branch and constitutes an element of a resonator which is so tuned that it resonates to and thus attenuates sound waves which contribute to the exhaust noise of the engine, and a silencer which includes two ducts of which one is connected to the exhaust port of one and the other to the exhaust port of the other of the other two cylinders, a shell which encircles the ducts and with them defines a compartment, partitions which subdivide the compartment lengthwise into a plurality of chambers of which each communicates with the ducts as a side branch and constitutes an element of a resonator which is so tuned that it resonates to and thus attenuates sound waves which contribute to the exhaust noise of the englue, and an expansion chamber through which each of the mentioned ducts is connected to the exhaust port to which it is connected.

2. In an internal combustion engine in which the exhaust period of a later firing cylinder overlaps the exhaust period of an earlier firing cylinder, a silencer which includes a plurality of ducts of which one is connected to the exhaust port of one and another to the exhaust port of the other of the mentioned cylinders but neither is connected to the exhaust port of a cylinder whose exhaust period overlaps the exhaust period of that of the first mentioned cylinders to which it 'is connected to the same extent as the exhaust period of the earlier firing is overlapped by the exhaust period of the later firing of the first mentioned cylinders, a shell which encircles the ducts and thus attenuates sound waves which contrib uated to the exhaust noise of the engine, and an expansion chamber through which each or the aavoaee mentioned ducts is connected to the exhaust port towhtch itis connected. r

3. In an internal combustion engine in which the interval the port ofa later firing cylinder is open overlaps the interval the corresponding port of. an earlier firing cylinder is open, a silencer which includes a plurality of ducts of which one is connected through an expansion chamber to the mentioned portv of one and another through an expansion. chamber tothe mentioned port of the other 01' the mentioned cylinders but neither is connected to the corersponding port of z'cylinder whose open'interval overlaps the open interval of that of the first; mentioned cylinders to which itis connected to the same extentas the open interval of the earlier firing is. overhpped by the open interval of the other later firing oi the first mentioned cylinders, and a shell which encircles the ducts and defines with them a compartment which communicates. with a. pluralzlty 01 the ducts as a side branch.

4, In an internal combustion engine in which the interval the port of one cylinder is open over laps, the interval the corresponding port of another cylinder is open, a silencer which includes a plurality of ducts of which one is connected through an expansion chamber to: the mentioned port of one and another through an expansion chamber to the mentioned port of the other of the mentioned cylinders but neither is connected to the corresponding port of a cylinder whose open interval overlaps the open interval of that, of the first. mentioned cylinders to which it is connected to the same extent as the open inter val of oneis overlapped by the open interval of thewother oi the first mentioned cylinders and a climber. with which a. plurality ofthe ducts commun-icate between their ends.

5. In a two stroke cyc'l'e internal combustionengine with four cylinders which are disposed radially and spaced equiangularly around the crankshaft and fire successively in the order in which they are arranged around the crankshaft with the exhaust period of each cylinder overlapping the exhaust period of the cylinder which fires immediately before it, a silencer which includes two ducts of which one is connected to the exhaust port of a cylinder and the other to the exhaust port of the cylinder which fires immediately after it, a shell which encircles the vducts and with them defines a compartment, partitions which subdivide the compartment lengthwise into a plurality of chambers of which each communicates with the ducts as a side branch and constitutes an element of a resonator which is so tuned that it resonates to and thus attenuates sound waves which contribute to the exhaust noise of the engine and a silencer which includes two ducts of which one is connected to the exhaust port of one and the other to the exhaust port of the other of the other two cylinders, a shell which encircles the ducts and with them defines a compartment, partitions which subdivide the compartment lengthwise into a plurality of chambers of which each communicates with the ducts as a side branch and constitutes an element or a resonator which is so tuned that it resonates to and thus attenuates sound waves which contribute to the exhaust noise of the engine.

6. In an internal combustion engine in which i the interval the port of one cylinder is open overlaps the interval the corresponding port of another cylinder is open and the interval the corresponding port of a third cylinder is open which the ducts overlaps the interval the corresponding port 01 aiourth cylinder is open, a silencer which includes two ducts of which one is connected to the mentioned portof one and the other to the mentioned'port of the other of the first mentioned cylinders, a chamber with which the ducts communicate betweentheir ends, and a silencer -which includes two ducts of which one is com nected to the mentioned port. of one and the other to the mentioned port of the other of the second mentioned cylinders and a chamber with communicate between their ends '7. In an internal combustion engine in which the exhaust period of a later firing cylinder overlaps the exhaustv period of an earlier firing cylinder, asilencer which includes a plurality of ducts of which one is connected to the exhaust port of one and another to the exhaust. port of the other of the mentioned cylinders but neither is connected to the exhaust port. of a cylinder whose exhaust period overlaps the exhaust period of that of the first mentioned cylinders to which it is connected to the same extent as the exhaust period of the earlier firing is overlapped by the exhaust period'ol the later firing of the first-mentioned cylinders, a shell which encircles the ducts and with them defines a compartment, and partitions which subdivide the compartment lengthl wise into aplurality of chambers of which each communicates: as a side branchand' with a plurality of ducts constitutes an; element of a resonator which is so tuned that it resonates to and thus attenuates sound waves which contribute to the exhaustnoiseoi the engine.

8. In an internal combustion engine in which the exhaust period of a later firing cylinder overlaps the exhaust. period of an earlier firing cylinder, a silencer which includes a. plurality of ducts of which one is connected to the exhaust port of one and: another to the exhaust port of the other of the mentioned cylinders but neither is connected to the exhaust port of a cylinder Whose exhaust period overlaps the exhaust period of that of the firstmentioned cylinders to which it is connected to the same extent as the exhaust period of one is overlapped by the exhaust period of the other of the first mentioned cylinders, and a shell which encircles the ducts and with them defines a compartment which communioatesas a side branch with a plurality of the ducts and is so tuned that it resonates to and thus attenuates sound waves which contribute to the exhaust noise of the engine.

9. In an internal combustion engine in which the exhaust period of one cylinder overlaps the exhaust period of another cylinder, a silencer which includes a plurality of ducts of which one is connected to the exhaust port of one and another to the exhaust port of the other of the mentioned cylinders but neither is connected to the exhaust port of a cylinder whose exhaust period overlaps the exhaust period of that of the first mentioned cylinders to which it is connected to the same extent as the exhaust period of one is overlapped by the exhaust period of the other another to the mentioned port of the other of the mentioned cylinders but neither is connected to the corresponding port of a cylinder whose open interval overlaps the open interval of that of the first mentioned cylinders to which it is connected to the same extent as the open interval of the earlier firing is overlapped by the open interval of the other later firing of the first mentioned cylinders, and a shell which encircles the ducts and defines with them a compartment which communicates with a plurality of the ducts as a side branch.

11. In an internal combustion engine in which the interval the port of one cylinder is open overlaps the interval the corresponding port of another cylinder is open, a silencer Which includes a plurality of ducts of which one is connected to the mentioned port of one and another to the mentioned port of the other of the mentioned cylinders but neither is connected to the corresponding port of a cylinder whose open interval overlaps the open interval of that of the first mentioned cylinders to which it is connected to the same extent as the open interval of one is overlapped by the open interval of the other of the first mentioned cylinders, and a plurality of chambers with each of which a plurality of ducts communicate between their ends.

12. In an internal combustion engine in which the interval the port of one cylinder is open overlaps the interval, the corresponding port of another cylinder is open, a silencer which includes a. plurality of ducts of which one is connected to the mentioned port of one and another to the mentioned port'of the other of the mentioned cylinders but neither is connected to the corresponding port of a cylinder whose open interval overlaps the open interval of that of the first mentioned cylinders to which it is connected to the same extent as the open interval of one is overlapped by the open interval of the other of the first mentioned cylinders, and a shell which encircles the ducts and defines with them a compartment which communicates with a plurality of the ducts as a side branch.

13. In an internal combustion engine in which the interval the port of one cylinder is open overlaps the interval the corresponding port of another cylinder is open, a silenter which includes a plurality of ducts of which one is connected to the mentioned port of one and another to the mentioned port of the other of the mentioned cylinders but neither is connected to the corresponding port of a cylinder whose open interval overlaps the open interval of that of the first mentioned cylinders to which it is connected to the same extent as the open interval of one is overlapped by the open interval of ,the other of the first mentioned cylinders, and a chamber with which a plurality of the ducts communicate between their ends.

14. In an internal combustion engine in which the interval the port of one cylinder is open overlaps the interval the corresponding port ofenother cylinder is open, a silencer which includes a plurality of ducts of which one is connected to the mentioned port of one and the other to the mentioned port of the other of the mentioned cylinders but neither is connected to the corresponding port of a cylinder whose open interval overlaps the open interval of that of the first mentioned cylinders to which it is connected to the same extent as the open interval of one is overlapped by the open interval of the other of the first mentioned cylinders, and a chamber which communicates as a side branch with a plurality of the ducts and is so tuned that it resonates to and thus attenuates sound waves which contribute to the noise of the engine which issues from the mentioned ports.

EDWARD V. RIPPINGILLE.

CERTIFICATE OF CORRECTION.

Patent No. 2,570,259. February 27, 191

EDWARD V. RIPPINGILLE.

It is hereby certified that error a pears in the printed specification of the above numbered patent reou iring correction as follows: Page 1, second column, line .25, after 1/11. strike out the closing parenthesis page 2, first column, line 61, for "here" read --herein-; page 5, second column,

line 52, claimT, for the word "ducts" read --the ducts and--; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 12th day of June, A. D. 1915.

Leslie Frazer (Seal) Acting Commissioner of Patents.

CERTIFICATE OF I CORRECTION. Patent No. 2,570,259. February 27 1915.

EDWARD V. RIPPINGILLE It is hereby certified that erroralipears in the printed specification of the above numbered patent requiring correction as follows: Page 1, sec- 0nd column, line 25, after l/l strike out the clotting parenthesis page 2, first co 111mm, line 61, for "here" read -herein--; page 3, second column, line 52, claimT, for the word "ducts" read -the ducts' and-; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 12th day of June, A. D. 191

Leslie Frazer (Seal) 3 Acting Commissioner of Patents. 

